Paul dietz



No. 770,564. Y PATENTED SEPT. 20, 1904. P. DIETZ.

VALVE GEAR.

APPL\IOATION FILED FEB. 19, 1904.

NO MODEL.

UNITED STATES Patented September QO, 1904.

PATENT QFFICE.

PAUL DIETZ, OF LEIPZIG, GERMANY, ASSIGNOR TO GUSTAV DIETZ, OF

NEW YORK, N. Y. I

VALVE-GEAR.

SPECIFICATION forming part of Letters Patent No. 770,564, dated September 20, 1904.

Application filed February 19, 1904. Serial No. 194,421. (No model.)

To all whom, it may concern:

Be it known that I,'PAUL DIETZ, acitizen of the Empire of Germany, residing in Leipzig, in the Kingdom of Saxony and Empire of Germany, have invented certain new and useful Improvements in Valve-Gears for Steam- Engines, of which the following is a specification. 7

This invention relates to an improved valvegear for steam-engines by which the lead of the slide-valve and the point of cut-01f can be regulated in a very simple and efiicient manner within certain limits, so that any desired variation in the supply of steam to the cylinder is obtained and the motion of the engine be conveniently reversed; and for this purpose the invention consists of a valve-gear for steam-engines which comprises a shaft to which rotary motion is imparted from the crank-shaft of the engine, said shaft being provided with cranks and an inclined portion between said cranks, a split eccentric on said inclined crank portion, means for connecting the sections of the eccentric, a yoke strapped on said eccentric, a slide-valve on the face of the steam-cylinder, a connecting-rod between the slide-valve and yoke, and means for shifting the slide-valve-governing shaft and its inclined crank portion so that the crank portion is moved from one side to the other of the eccentric.

The invention consists, further, of the specific construction of theeccentric, which is composed of two split sections that are connected by transverse screw-bolts, so as to permit the convenient placing of the eccentric on the inclined crank portion of the slide-.valve-controlling shaft; and the invention consists, further, of certain details of construction for regulating the lead of the slide-valve,as will be fully described hereinafter, and finally pointed out in the. claims.

In the accompanying drawings, Figure 1 represents a sectional side elevation of my improved valve-gear for steam-engines. Fig. 2

is a vertical section through the steam-cylinder, showing the valve-gear connected with the slide-valve in sectional end view. 'Fig. 3

.slide-valve-operating shaft, so that by the recis a sectional side elevation of the valve-gear, showing the same in position for reversing the motion of the slide-valve. Figs. 4, 5, and 6 are vertical transverse sections showing the different positions of the eccentric on the crank portion of the slide-valve-controlling shaft respectively for forward motion, intermediate position in which no steam is supplied to the cylinder, and in position for reversing the motion of the slide-valve; and Fig. 7 is a diagram showing graphically the difierent positions of the eccentric and the angle of advance of the, valve.

Similar letters of reference indicate corresponding parts. My improvedvalve-gear is intended to produce the regulation of lead and the point of cut-0H of the slide-valve of a steam-engine in a simple and effective manner, so as to control the variation of the steam supplied to the cylinder, the expansive action of the same on the piston, and the reversing of the motion of the engine. This isaccomplished in such a manner that the connecting-rod of the slidevalve is operated from an eccentric which is located on an inclined crank portion of the tilinear shifting of the shaft in the direction of its axis the position of the inclined crank portion in the eccentric is changed from the position of the slide-valve for forward motion to an intermediate or non-acting position of the slideevalve or to a position for reversing the motion of the same, so that a variable lap is imparted to the slide-valve and a variable charge of steam supplied to the cylinder.

In the drawings, Figs. 1 and 3 represent two different positions of the slide-valve-operating shaft w in the eccentric, Fig. 1 showing the position of the shaft for controllingthe forward motion of the slide-valve and Fig. 3 the position of the shaft for reversing the motion of the same. The shaft w is guided in stationary journal-bearings and moved in the lineof its axis from one side to the other by a lever h, that is applied to one endof the shaft w. At intermediate points of the shaft w are arranged cranks f, which extend in diametrically opposite direction to each other over the ports of the steam-cylinder without 65 from the shaft w, said cranks being connected by an inclined crank portion f, which on the rectilinear shifting of the shaftw moves from one side to the other of an eccentric g, that is located onthe inclined crank portion f. Ro-

tary motion is transmitted from the crankshaft 3 of the steam-engine to the slide-valveoperating shaft w by a bevel-gear or other suitable transmission.

The eccentric g is connected by a yoke g strapped around the same, and a connectingrod with the rod of a slide-valve s of the steam-cylinder 0, as shown in Fig. 2. The shaft to is arranged parallel with the crankshaft 3/ of the engine, the inclined portionf' being located at a suitable angle tothe axis of the shaft w, as shown in Figs. 1 and 3.

The eccentric is constructed of two sections g g asmaller section, 9, and a larger section,

7 which are connected by transverse bolts the heads and nuts of which are arranged in countersunk recesses of the sections g g as shown clearly in Fig. 4:. In the smaller section, 9, is formed a recess which corresponds in inclination and cross-section to that of the inclined crank portion f, the crosssection being preferably square, so as to prevent the axial shifting of the eccentric on the inclined crank portion f. I 1

The hand-lever h, by which the shifting motion of the slide-valveoperating shaft w is controlled, is moved along and locked to a guide-segment in the usual manner. when the hand-lever h is shifted toward the right, the shaft w is shifted in its journal-bearings toward the right and simultaneously the inclined crank portion f" in the eccentric When the median point of the inclined crank portion f arrives at the center of the eccentric g, a short stroke is imparted to the slidevalve, which is not sufficient to uncover the portsof the same, so that no steam is trans-- mitted to the cylinder, whereby the motion of the engine is interrupted. When the shaft w is shifted still more toward the right, the inclined crank portion is shifted entirely to the opposite end of the eccentric g, so that the motion of the slide-valve and the motion of the engine are reversed. From the yoke extends a guide-rod t in downward direction, said guide-rod being a continuation of the connecting-rod t and guided in a keeper i, so that any side motion of the connectingrod is prevented. The lever h is connected by a swivel-joint with the shaft w, so that the latter can be rotated without being interfered with by the lever it. The lap of the slide- Valve on the face of the cylinder is controlled by the position of the eccentric g on the inclined crank portion of the shaft w, the maximum lap of the slide-valve being equal to 2 6b. In the median position of the inclined crank portion in the eccentric the slide-valve moves opening the same, its stroke being still 2 a". No steam can enter to the cylinder, and the engine assumes a position of rest.

For reversing the engine or for increasing ordecreasing the supply of steam to the cylinder the inclined crank portion is moved in the eccentric by the shifting of the slide-valveoperating shaft w, the center of the eccentric always remaining on the line 1 1, Figs. lto 6, Fig. 4 showing the position of the eccentric for the forward motion, Fig. 5 its position of rest, and Fig. 6 the position for reversing the motion of the engine. The valve-gear permits the adjustment of the angle of advance of the eccentric, and consequently a variable lead of the slide-valve and a variable supply of steam to the steam-cylinder. In Fig. 7 the angle of advance for forward and reverse motion is graphically shown, while the theoretical position of the crank for the different positions is shown by a heavy line, and the distance between the center line of the shaft 10 and the center of the eccentric is indicated by t b, and the distance between the extreme positions of the eccentric by 2 a. When it is desired to regulate the lead of the valve in addition to the point of cut-off of the same, the groove 1" on the shaft w is used. Said groove is made either in the form of a curved groove or in the form of a long pitched raised screw-thread, and the bevel-gear 1- may be adjusted along the same. When the lead of the valve is to be changed, either a lug on bevel-gear 1" is made to engage said groove and the ordinary key-fastening removed or stationary means (not shown) are used to engage the same. It will be readily seen, therefore, that when the groove 1" is engaged in this'manner the shaft w in being adjusted transversely is rocked about its center in either direction desired, thus changing the distance from the eccentric to the valve, and consequently the lead of the latter. The quantity of steam entering the engine remains the same; but its lead is adjusted by the offset or curved groove 1* on the shaft w.

My improved valve-gear has the following advantages: first, that by the adjustment of the angle of advance the lead of the slideval've,and thereby the variable supply of steam to the same and to some extent the expansion,

IIO

and an inclined crank portion between the being-provided with an inclined recess fittingv said crank portion, means for connecting said sections, means for shifting the shaft in the eccentric for the full length of the crankportion, a yoke strapped to said eccentric, a slide-valve on the engine, and a connecting-rod between the yoke and said slide-valve, substantially as set forth.

2. In a reversing-gear for steam-engines, the combination, with a slide-valve-controlling shaft provided with cranks extending at diametrically opposite points and an inclined crank portion between said cranks, of a slidevalve -controlling eccentric on said inclined crank portion composed oftwo sections,- the smaller section being provided with a recess corresponding to the cross-section and inclination of the crank portion, a larger section, and transverse bolts for connecting the sections of the eccentric, the heads and screw-nuts of the bolts being arranged in countersunk recesses of said sections, substantially as set forth.

3. In a reversing-gear for steam-engines, the combination, with a slide-valve and its controlling-shaft provided with an inclined crank portion, of an eccentric on said crank portion connected with said slide-valve, a member on said controlling-shaft'for transmitting motion from the crank-shaft of the engine and means for axially shifting said motion-transmitting member on said controlling-shaft for regulating the lead of the slide-valve, substantially as set forth.

4:. In a reversing-gear for steam-engines, the combination, with a slide-valve and its controlling-shaft provided with an inclined crank portion, of an eccentric on said crank portion connected with the slide-valve, means for transmitting rotary-motion to the slide-valve-controlling shaft from the crank-shaft of the engine, a longitudinal ofi set or curved groove in said shaft, and means for adjusting the motiontransmitting member on the grooved portion of the shaft for regulating the lead of the slidevalve, substantially as set "forth.

In testimony that I claim the foregoing as my invention 1 have signed my name in presence of twosubscribing witnesses.

, 7 PAUL DIETZ. Witnesses: 1

RUDOLPH FRIOKE, LEON ZEITLIN. 

